import java.util.concurrent.Semaphore;

/**
 * 测试Semaphore
 * 模拟两个线程对count进行操作
 * 它是线程安全的
 */
public class Semaphore2 {
    static int count = 0;
    public static void main(String[] args) throws InterruptedException {
        Semaphore semaphore = new Semaphore(1);


        Thread t1 = new Thread(() -> {
            for (int i = 0; i < 50000; i++) {
                try {
                    semaphore.acquire();
                    count++;
                    semaphore.release();
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
        });

        Thread t2 = new Thread(() -> {
            for (int i = 0; i < 50000; i++) {
                try {
                    semaphore.acquire();
                    count++;
                    semaphore.release();
                } catch (InterruptedException e) {
                    throw new RuntimeException(e);
                }
            }
        });

        t1.start();
        t2.start();
        t1.join();
        t2.join();

        System.out.println(count);
    }
}
